The present invention relates to a document retrieval assisting method having a user interface with an interactive guidance function realized therein and a document retrieval service or document retrieval assisting service utilizing the same.
For document retrieval systems, a variety of assisting functions have been designed and developed so that users might readily reach a desired document assembly as soon as possible. Feedback and guidance are primary ones among them. Feedback is such a mechanism that, when a user draws his determination of YES/NO concerning several items from search results, search results reflecting the determination can then be gained, as is described for example in G. Salton, J. M. McGill (1983), Introduction to Modern Information Retrieval, McGraw-Hill, Chapter 6. Further, guidance is a function to provide information relevant to a retrieval operation at the individual processes of the retrieval operation, namely information believed to possibly work as reference when a user intends to modify or improve search queries.
As to the guidance function, conventionally, a method has generally been executed, comprising proposing information relevant to input search queries. For example, a method is illustrated, comprising storing a database representing relations between words, such as thesaurus, and retrieving from the data base, a set of words relevant to the input keywords. Thesaurus is a tree-structure database primarily showing the xe2x80x9cis-axe2x80x9d relations between words, and furthermore, a method is also suggested, comprising automatically generating a data of relevant words using co-occurrence statistics (see for example Japanese Patent Laid-open No. Hei 8-161343 entitled xe2x80x9cRelated Word Dictionary Preparing Devicexe2x80x9d; or see B. R. Schatz et al. (1966), Interactive term suggestion for users of digital libraries: Using subject thesauri and co-occurrence lists for information retrieval, Proc. ACM DL""96, pp. 126-133). R. H. Fowler and D. W. Dearholt also propose, in xe2x80x9cInformation Retrieval Using Pathfinder Networksxe2x80x9d, in R. W. Schvaneveldt ed., Pathfinder Associative Networks, Ablex, Chapter 12 (1990), a method comprising displaying a search word and words relevant to the word in a network structure, on the basis of the co-occurrence statistic data between words.
However, the method providing information relevant to a query is disadvantageous in that the method is hardly applicable to a case with a plurality of search words or a case with negation used; and the method is also problematic in that the method is hardly applicable to document retrieval with no use of any key word (associative search). So as to overcome these problems, a method is proposed, comprising automatically extracting relevant information from search results and providing the information to a user. For example, Scatter/Gather method [D. Cutting, et al. (1992), Scatter/Gather: A Cluster-based Approach to Browsing Large Document Collections. Proc. ACM SIGIR""92, p. 318-329] comprises automatically classifying a retrieved document group (clustering) and displaying the topic words per each class. U.S. Pat. No. 5,987,460 submitted by the present inventors proposes a method for preparing and displaying a topic word graph, comprising extracting topic words from search results and extracting the co-occurrence relation between the topic words.
However, these conventional methods are disadvantageous in that the interaction between the display area of title list as primary information of search results and guidance information is so insufficient that users cannot sufficiently utilize the guidance information.
From the standpoint of search style, complementary two search types, namely key word search and associative search, are required, but disadvantageously, no user interface exists, which is capable of selecting and using one of them, depending on the search queries, to execute guidance within the same frame.
So as to overcome the aforementioned problems of the prior art, it is an object of the present invention to attain that users can catch both individual information such as title list as search results and the over view of the search results such as a topic-word graph and try to improve the search queries while analyzing the relation between the individual information and the overview or to carry out retrieval from another standpoint; and it is the other object of the present invention to attain that a user can readily retrieve a set of documents highly related to same an interesting documents for the user or to some documents owned by the user or to some interesting documents or a part thereof the user has encountered during the course of retrieval operation.
So that users might make attempts for improving search queries while catching the whole set of search results or for performing retrieval from another standpoint, the overview information in the form of a topic-word graph along with the list of titles as primary information of search results, is mapped at readily comparable positions on the same image, thereby enabling the utilization of the displayed topic words as search words through click operation with mouse, or selecting some of the displayed topic words through simple mouse operation to make an emphasized display of titles including them or concentrating the emphasized titles toward the top of the lists, which promotes ready identification of the relation between the topic words and documents including them, or alternatively selecting some of the titles to make an emphasized display of topic words contained in these documents, so that a retrieval assisting interface for propagating more deepened search can be achieved.